1. Field of the Invention
The present invention relates to writing instruments, such as fountain pens and mechanical pencils, having a cap provided with a clip, and relates in particular to means for securing together the end piece of the cap and the clip.
2. Description of the Prior Art
In most writing instruments having a cap, the end piece of the latter comprises an additional or separate piece generally screwed to the body of the cap. Such an arrangement enables manufacture of the cap to be simplified by making it possible, for example, to use shaped tubes. Because of improved accessibility, this arrangement also improves maintenance of any mechanism internal to the cap.
However, it has been found that, after a certain length of time in service, cap end pieces mounted in this way tend to unscrew or otherwise become loose. This drawback is all the more serious in that most of the time such an end piece also holds the clip of the writing instrument in place.
To prevent the end piece from becoming accidentally unscrewed, it has been proposed that a washer of the spring lock washer type be wedged between the cap and the end piece. However, since this method of immobilization is unattractive in appearance, it is suitable for use only in inexpensive writing instruments.